7T Magnetic Resonance Translational Medicine Research Center, Department of Radiology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.
School of Psychology, Shandong Normal University, Jinan, China.
Eur J Neurol. 2024 Sep;31(9):e16368. doi: 10.1111/ene.16368. Epub 2024 Jun 24.
Human motor planning and control depend highly on optimal feedback control systems, such as the neocortex-cerebellum circuit. Here, diffusion tensor imaging was used to verify the disruption of the neocortex-cerebellum circuit in spinocerebellar ataxia type 3 (SCA3), and the circuit's disruption correlation with SCA3 motor dysfunction was investigated.
This study included 45 patients with familial SCA3, aged 17-67 years, and 49 age- and sex-matched healthy controls, aged 21-64 years. Tract-based spatial statistics and probabilistic tractography was conducted using magnetic resonance images of the patients and controls. The correlation between the local probability of probabilistic tractography traced from the cerebellum and clinical symptoms measured using specified symptom scales was also calculated.
The cerebellum-originated probabilistic tractography analysis showed that structural connectivity, mainly in the subcortical cerebellar-thalamo-cortical tract, was significantly reduced and the cortico-ponto-cerebellar tract was significantly stronger in the SCA3 group than in the control group. The enhanced tract was extended to the right lateral parietal region and the right primary motor cortex. The enhanced neocortex-cerebellum connections were highly associated with disease progression, including duration and symptomatic deterioration. Tractography probabilities from the cerebellar to parietal and sensorimotor areas were significantly negatively correlated with motor abilities in patients with SCA3.
To our knowledge, this study is the first to reveal that disrupting the neocortex-cerebellum loop can cause SCA3-induced motor dysfunctions. The specific interaction between the cerebellar-thalamo-cortical and cortico-ponto-cerebellar pathways in patients with SCA3 and its relationship with ataxia symptoms provides a new direction for future research.
人类运动规划和控制高度依赖于最优反馈控制系统，例如新皮层-小脑回路。在这里，我们使用弥散张量成像来验证 3 型脊髓小脑共济失调（SCA3）中皮质-小脑回路的中断，并研究该回路的中断与 SCA3 运动功能障碍的相关性。
本研究纳入了 45 名年龄在 17-67 岁之间的家族性 SCA3 患者和 49 名年龄和性别相匹配的健康对照者，年龄在 21-64 岁之间。使用患者和对照者的磁共振成像进行基于束流的空间统计学和概率追踪分析。还计算了从小脑追踪到的概率追踪的局部概率与使用特定症状量表测量的临床症状之间的相关性。
小脑起源的概率追踪分析显示，结构连接，主要是皮质下小脑-丘脑-皮质束，在 SCA3 组中明显减少，而皮质-桥脑-小脑束在 SCA3 组中明显增强。增强的束延伸到右侧顶侧区域和右侧初级运动皮层。增强的皮质-小脑连接与疾病进展高度相关，包括病程和症状恶化。小脑到顶叶和感觉运动区的追踪概率与 SCA3 患者的运动能力呈显著负相关。
据我们所知，这项研究首次揭示了破坏皮质-小脑回路可能导致 SCA3 引起的运动功能障碍。SCA3 患者小脑-丘脑-皮质和皮质-桥脑-小脑通路之间的特定相互作用及其与共济失调症状的关系为未来的研究提供了新的方向。
